Virtualisation isn't the only way to try a new distribution – it just happens to be the most unobtrusive and easiest to use. But if you want to take your testing a little more seriously, running a new release on your own hardware without messing up your primary installation, there are several techniques that can help make the process easier.
Unlike a couple of commercial operating systems we could mention, most modern Linux distributions will quite happily install themselves alongside other operating systems and distributions, automatically adding their boot options to a boot menu.
Resizing is then a simple matter of selecting the partition you want to shrink (or enlarge) and clicking on the Resize button. From the window that appears, drag either the left or right border of the partition to shrink the space it occupies on the drive.
After you've mastered the art of manual partitioning, there's another useful aspect to taking control of your data, and that's creating a separate home partition. You just need to create another partition alongside root and swap, give it a filesystem and assign it a mount point of /home.
Most installations will let you choose an existing partition to use as home and won't require it to be reformatted as part of the process. This means that any user accounts, along with their data, will appear intact and accessible from the moment you boot into the new distribution, which is especially useful if your time happens to be spread across more than one distro.
We would recommend creating a separate user for each distribution. This avoids any potential overlap in home directories and configuration files when you create a user account that already exists in a different distribution.
If you want to port your settings from one account to another, you can do that manually with the command line after you get the desktop up and running. Just copy the entire contents of one home directory to another using the cp -rf source destination command and make sure the owner and group permissions are adjusted to reflect the user who's going to access the new directory (try chmod -R username:username directory).
Even if you can't work with manual partitions, there's still the easiest option of all, and that's the humble live CD. Many distributions now include their own bootable versions, enabling you to test a distribution for hardware compatibility as well as for its design and usability. You can get a very good idea of what the final installation may feel like from a distribution running off a CD, even if the slow data read times from the optical disc may things a little slow.
Distro on a stick
This speed issue can be solved by installing any distribution you may want to try on to a spare USB thumbdrive and booting from this when you restart your machine. Creating a USB-based distribution like this used to be a chore, but thanks to the Unetbootin tool, you can create a bootable stick for all the most common distributions with just a few clicks of the mouse.
Most distributions will include the Unetbootin package, and the application itself will likely need administrator privileges. When it's running, just point it at the location of your distribution's ISO and select the distribution version from the drop-down lists, followed by the location of your memory stick.
Any PC from the last 3–5 years should be able to boot from the USB drive without any further interaction, but sometimes you may need to enter a boot menu from the BIOS, or change the boot order in the BIOS itself.
The end result will be a distro running from external storage with almost the same speed of a native distribution.